Antenna assembly including a dual flow rotating union

ABSTRACT

An antenna assembly including a first rotating pedestal including an antenna thereon, a second pedestal supporting the first pedestal, and a dual flow rotating union having a longitudinal axis. The dual flow rotating union includes a rotating housing portion coupled to the first rotating pedestal, a stationary housing portion coupled to the second stationary pedestal, and a conduit located in the housing portion. The conduit has opposing ports oriented parallel to the longitudinal axis, a rotating section and a stationary section. One said conduit port is located on the rotating section, and the other conduit port is located on the stationary section. The housing also has opposing ports oriented parallel to the longitudinal axis. One housing port is located on the stationary portion, and the other said housing port is located on the rotating portion.

RELATED APPLICATIONS AND PRIORITY CLAIM

This application is a divisional application of prior U.S. patentapplication Ser. No. 10/175,761 filed on Jun. 20, 2002, now U.S. Pat.No. 6,851,724, which is hereby incorporated herein by reference, and towhich this application claims priority.

GOVERNMENT RIGHTS

The U.S. Government has a paid-up license in this invention and theright in limited circumstances to require the patent owner to licenseothers on reasonable terms as provided by the terms of Contract No.N00024-99-C-5380 awarded by the U.S. Navy.

FIELD OF THE INVENTION

This invention relates to an improved rotating union and, in oneexample, a dual flow rotating union for delivering and returning a largevolume of fluid through ports preferably aligned parallel to thelongitudinal axis of the union.

BACKGROUND OF THE INVENTION

Many rotating systems such as phased array antennas aboard ships requireliquid cooling for reliable operation. Phased array antennas are largestructures and can be attached to an oscillating pedestal normallylocated on a ship's deck.

Because of their large size, the liquid cooling system for such antennasare located off the rotating pedestal. Typically, fluid coolant passesto and from the rotating antenna at high flow rates and pressuresthrough a relatively narrow space. In military applications, the liquidcooling delivery system must be able to survive high shock loads.Therefore, complex delivery systems consisting of numerous parts arebound to experience more failures than delivery systems with lesscomponents. Lighter weight systems with a minimum of performanceproblems are desired. Additionally, leakage of liquid coolant onto thedeck of a ship must be avoided.

Accordingly, because of the lack of space and the various loadsinvolved, pedestal mounted phased array antennas offer unique challengesfor the design of the coolant delivery system, especially the dual flowrotating union, also referred to as a liquid rotary joint.

Currently known dual flow rotating unions have a rotating portion, astationary portion, and at least one port running perpendicular to therotation axis making packaging of such assemblies difficult. The use ofa perpendicular ports also requires larger bearings to withstand themoment loads due to the cantilevered connection to the perpendicularport. Thus, the overall system size and complexity is increased.

Also, currently known dual flow rotating unions that deliver fluidthrough a rotating axis are large, complex, and heavy units. Moreover,known rotating unions typically utilize a face seal between the fixedand rotating conduits. Face seals, unfortunately, require a largeenvelope size and thus increase the size of the system. Face seals alsorequire strict tolerances, thus increasing the complexity and cost ofthe system as well as increasing the potential for system malfunctionsor failures. Moreover, face seals do not work well in oscillatingapplications, such as the phased array antenna system described above.

Furthermore, currently known rotating unions normally require fluid flowthrough each conduit to be in the same direction for eventual mixing ofthe fluids, without the capability for delivery and return of the fluidswhile keeping the fluids in each conduit separate throughout thedelivery and return process. In addition, currently known dual flowrotating unions have no provision for leak containment or leak detectionat the onset of seal wear or failure.

In summary, no currently available rotating union meets the uniquerequirements of a phased array antenna system or similar systems.

SUMMARY OF THE INVENTION

It is therefore an object of this invention to provide a morestreamlined, lighter weight, less complex, more robust, and improveddual flow rotating union.

It is a further object of this invention to provide such a dual flowrotating union with all of the ports thereof aligned parallel to thelongitudinal axis of the union and parallel to the axis of rotation ofthe rotating portion of the union.

It is a further object of this invention to provide such a dual flowrotating union which delivers and returns fluid in the direction of thesame axis.

It is a further object of this invention to provide such a dual flowrotating union which eliminates the need for face seals.

It is a further object of this invention to provide such a dual flowrotating union which provides a contained pathway for small leaks andwhich allows for leak detection at onset of seal wear-out or failure.

It is a further object of this invention to provide such a dual flowrotating union which can be used in oscillating systems.

It is a further object of this invention to provide such a dual flowrotating union which can accommodate high volume fluid flows andpressures and which is able to survive large shock loads.

It is a further object of this invention to provide such a dual flowrotating union which can provide for both the delivery return of fluidsalong separate paths and in different directions.

The invention results from the realization that a more streamlined andless complex dual flow rotating union is effected by an inner conduitwhich curves in a serpentine fashion from a stationary inlet port to arotating outlet port both located at the outer extent of the union andwherein the conduit curves such that the junction between the rotatingportion of the conduit and the stationary portion of the conduit islocated on the longitudinal axis of the union. The union housing, whichsurrounds the serpentine conduit, has a rotating inlet port and astationary outlet port both also located at the outer extent of theunion. In this way, all the ports of the union can be oriented parallelto the longitudinal axis of the union providing a more streamlined unionwith fairly large diameter flow ports capable of accommodating largevolumes of cooling liquid and eliminating the need for the right angleports of the prior art. Moreover, in such a design, the face seals usedin prior art unions—seals which are large and complex and which cannot,in any event, be used in oscillating implementations such as antennaarrays—can be avoided and replaced with more simple soft radial seals.

This invention features a dual flow rotating union having a longitudinalaxis, the union including a conduit having opposing ports preferablyoriented parallel to the longitudinal axis. The conduit has a rotatingsection and a stationary section, one conduit port is located on therotating section, the other conduit port is located on the stationarysection. A housing is disposed about the conduit and has opposing portspreferably oriented parallel to the longitudinal axis. The housing alsoincludes a stator portion and a rotor portion rotatably disposed withrespect to the stator portion. One housing port is located on the statorportion, the other housing port is located on the rotor portion.Preferably, the conduit curves such that a distal end of the rotatingsection of the conduit rotatably mates with a proximal end of thestationary section of the conduit at a location on the longitudinal axisof the union. The distal end of the rotating section of the conduit istypically received in the proximal end of the stationary section of theconduit.

The dual flow rotating union of the present invention may furtherinclude a combined bearing and seal made of carbon and teflon locatedbetween the proximal end of the stationary section of the conduit andthe distal end of the rotating section of the conduit.

The dual flow rotating union of the present invention may furtherinclude a bearing assembly disposed between the distal outer wall of therotor portion of the housing and the proximal inner wall of the statorportion of the housing. Also, a radial seal is disposed between thedistal outer wall of the rotor portion of the housing and the proximalinner wall of the stator portion of the housing. A seepage port may alsobe included disposed between the proximate inner wall of the statorportion of the housing and a proximate outer wall of the stator portionof the housing.

The rotor portion of the housing typically has a distal outer wallrotatably received within the proximal inner wall of the stator portionof the housing. The rotating section port of the conduit may be disposedadjacent the rotor port of the housing and the stationary section portof the conduit may be disposed adjacent the stator port of the housing.In a preferred embodiment, the rotor portion of the housing and therotating section of the conduit have an axis of rotation the same as thelongitudinal axis.

In one example, the housing forms another conduit between the housingport located on the stator portion and the housing port located on therotor portion. The rotor portion of the housing may oscillate along withthe rotating portion of the conduit, and flow through the conduit maybe, in one example, in a direction opposite flow through the housing, ormay be in the same direction.

This invention further features a dual flow rotating union having alongitudinal axis, the union preferably including a conduit havingopposing output ends oriented parallel to the longitudinal axis. Theconduit may include a rotating section and a stationary section with oneconduit output end located on the rotating section and the other conduitoutput end located on the stationary section. A housing may be disposedabout the conduit, and the housing may have opposing output endsoriented parallel to the longitudinal axis. The housing may furtherinclude a stator portion and a rotor portion rotatably disposed withrespect to the stator portion with one housing output located on thestator portion and the other housing output located on the rotorportion. In one example, the conduit curves such that the distal end ofthe rotating section of the conduit rotatably mates with the proximalend of the stationary section of the conduit at a location on thelongitudinal axis of the union.

This invention also features a rotating union with a serpentine conduithaving first and second sections one of which rotates with respect tothe other. The distal end of the first conduit section is rotatablycoupled to the proximal end of the second conduit section at a locationon the longitudinal axis of the union. The rotating union may furtherinclude a housing disposed about the serpentine conduit. The housing hasa first portion which rotates with respect to a second portion. Thedistal end of the first housing portion is typically rotatably coupledto the proximal end of the second housing portion.

Additionally, this invention features a dual flow union including arotor housing with two parallel ports, a stator housing with twoparallel ports, a conduit disposed in the rotor housing and the statorhousing interconnecting one rotor port with one stator port. Preferably,the sum of the perimeter of the rotor ports is a dimension the sameorder of magnitude as the perimeter of the rotor housing and the sum ofthe perimeter of the stator ports is a dimension the same order ofmagnitude as the perimeter of the stator housing.

This invention also features a dual flow union having a rotor housingwhich includes two spaced parallel ports, a stator housing including twospaced parallel ports, and a conduit interconnecting one rotor port withone stator port. Typically, both of the rotor ports are locatedproximate the periphery of the rotor and both of the stator ports arelocated proximate the periphery of the stator.

This invention further features a rotary joint for transferring fluidincluding a housing with a first portion having an input port alignedparallel to the longitudinal axis of the housing, and a second portionwith an output port aligned parallel to the longitudinal axis. The firstand second portions are rotatable with respect to one another. A channelwithin the housing includes an input port aligned parallel to thelongitudinal axis.

In addition, this invention features an antenna assembly including afirst rotating pedestal with an antenna mounted thereon, and a secondpedestal supporting the first pedestal. A dual flow rotating unioncomprises a rotating housing portion coupled to the first rotatingpedestal and a stationary housing portion coupled to the stationarypedestal. A conduit located in the housing portion has opposing portsoriented parallel to the longitudinal axis of the union. The conduitincludes a rotating section and a stationary section. One conduit portis located on the rotating section and the other conduit port is locatedon the stationary section. The housing may also include opposing portsoriented parallel to the longitudinal axis. One housing port is locatedon the stationary portion and the other housing port is located on therotating portion.

This invention further features a dual flow rotating union having alongitudinal axis including a conduit having opposing ports preferablyoriented parallel to the longitudinal axis. The conduit has a firstsection and a second section, one conduit port located on the firstsection, the other conduit port located on the second section. The firstsection is rotatable relative to the second section. A housing isdisposed about the conduit and has ports preferably oriented parallel tothe longitudinal axis. The housing also includes a first portion and asecond portion rotatably disposed with respect to the first portion. Onehousing port is located on the first portion and the other said housingport is located on the second portion.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects, features and advantages will occur to those skilled inthe art from the following description of a preferred embodiment and theaccompanying drawings, in which:

FIG. 1 is a schematic view of a rotating, oscillating, phased arrayantenna system;

FIG. 2 is a schematic view of a prior art dual rotating union showingtwo right angle ports;

FIG. 3 is a cross-sectional schematic view of the prior art dualrotating union of FIG. 2;

FIG. 4 is a schematic three-dimensional view of a dual flow rotatingunion in accordance with the present invention;

FIGS. 5–6 are partially broken away highly schematic views of the unionshown in FIG. 4;

FIG. 7 is a schematic top view of the stationary section of the union ofFIGS. 4–6;

FIG. 8 is a schematic side view of the rotating section of the union ofFIGS. 4–6;

FIG. 9 is a cross-sectional front view of the union of FIGS. 4–6;

FIG. 10 is a cross-sectional side view of the union of FIGS. 4–6; and

FIG. 11 is a highly schematic view of the radial seal of the dual flowrotating union of this invention.

DISCLOSURE OF THE PREFERRED EMBODIMENT

As discussed in the background section above, phased array antennasystem or antenna assembly 10, FIG. 1, includes rotating pedestal 12including antenna 14 thereon. Typically, rotating pedestal 12 is locatedabove the deck level of a ship as indicated by line 16. Below deck levelis second pedestal 18. As also disclosed in the background sectionabove, large volumes of fluid coolant must pass to and from rotatingantenna 14 at a rate of up to 300 gallons per minute. But, because ofits large size, the liquid cooling system is typically not located onany portion of rotating pedestal 12, or on second pedestal 18. Thus,coolant must be piped to and from antenna 14 through rotating union 20.In military applications, rotating union 20 must be able to survive highshock loads.

Prior art union 22, FIG. 2 includes stationary section 24, rotatingsection 26, and two right angle ports 28 and 30 on stationary section24. These perpendicular ports cannot be used in conjunction with antennasystem 10, FIG. 1, because they require an area larger than the areaavailable in antenna system 10. Moreover, prior art rotating union 22includes face seal 32, FIG. 3, which requires a large envelope sizeincreasing the size of the union. Face seals also require stricttolerances, thus increasing the complexity and cost of the system aswell as increasing the potential for system malfunctions or failures.Moreover, face seals do not work well in oscillating applications suchas the phased array antenna system described with respect to FIG. 1. Theother shortcomings associated with prior art rotating union 22, FIGS.2–3 are described in more detail in the background section above.

Dual flow rotating union or rotary joint 40, FIG. 4, in accordance withthis invention, does not include the right angle ports of the prior artrotating union shown with respect to FIGS. 2 and 3. In one embodiment ofthis invention, dual flow rotating union 40 includes housing 42 withfirst or stator portion 44 and second or rotor portion 46. Multiplehousings (not shown) may be used to create multiple channels. Housingport 48 is located on stator portion 44 and housing port 50 is locatedon rotor portion 46. Housing ports 48 and 50 are opposing ports and areparallel to the longitudinal axis 80 of union 40. See FIGS. 5 and 6.Rotating union 40 also includes channel or conduit 60 having first orrotating section 62 and second or stationary section 64. Conduit port 66is located at the proximal end 67 of rotating conduit section 62 andconduit port 68 is located at the distal end 69 of stationary conduitsection 64. Conduit ports 66 and 68 are opposing ports and are parallelto the longitudinal axis 80 of union 40. As shown, conduit 60 curvessuch that distal end 70 of rotating section 62 rotatably mates withproximal end 72 of stationary section 64 at a location on longitudinalaxis 80 of union 40. Distal end 70 of the rotating section of theconduit 62, in this example, is received in the proximal end 72 of thestationary section of the conduit 64. In FIG. 6, rotor portion 46 ofhousing 42 and rotating conduit section 62 have rotated 180° from theposition shown in FIG. 5.

A top view of the housing 42 of dual flow rotating union 40 inaccordance with the present invention is shown in FIG. 7. Stationarysection 64 of conduit 60, conduit port 68, the proximal end 72 ofstationary section 64, and housing port 48 are also shown. In FIG. 8,the rotor portion 46 including housing port 50, conduit port 66, and thedistal end 70 of conduit section 62 are shown.

A seal and a bearing are typically located between the proximal end 72of stationary section 64 of conduit 60 and distal end 70 of rotatingsection 62 of conduit 60, FIG. 9. In the preferred embodiment, combinedseal and bearing 90 is employed and is disposed between proximal end 72of stationary section 64 of conduit 60 and distal end 70 of rotatingsection 62 of conduit 60, and can be made of carbon and teflon but isnot limited to these materials. Soft radial seals can also be used. Dualflow rotating union 40 further includes bearing assembly 100 disposedbetween distal outer wall 102 of rotor portion 46 of housing 42 andproximal inner wall 104 of the stator portion 44 of housing 42. Radialseal 110 is also disposed between distal outer wall 102 of the rotorportion of the housing and the proximal inner wall 104 of the statorportion of the housing. More than one radial seal 110, 110′ may beutilized. In the preferred embodiment, a seepage port 112, FIG. 10, isincluded in fluid communication with a containment vessel or the coolantreservoir (not shown). Seepage port 112 is typically disposed throughthe proximal inner wall 104 of the stator portion of the housing and aproximal outer wall 106 of the stator portion of the housing, boredbetween radial seals 110 and 110′, and together with the containmentvessel prevents leakage of liquid coolant, for example, onto the deck ofthe ship in the event of seal wear.

In the preferred embodiment as shown in FIG. 9, rotor portion 46 ofhousing 42 has a distal outer wall 102 rotatably received withinproximal inner wall 104 of stator portion 44 of the housing. Also asshown, rotating port 66 of the conduit 60 is disposed adjacent rotorport 50 of housing 42 and stationary section port 68 of the conduit isdisposed adjacent stator port 48 of the housing. Rotor portion 46 ofhousing 42 has an axis of rotation the same as longitudinal axis 80, andthe rotating section of conduit 62 has an axis of rotation the same aslongitudinal axis 80. Also, housing 42 forms conduit 140, FIG. 9,between housing port 48 located on stator portion 44 and housing port 50located on rotor portion 46. Rotor portion 46 of the housing androtating portion 62 of the conduit and housing port 50 may be used inoscillating applications. Typically, flow through conduit 60 can be adirection opposite the flow through the housing 140. In one example,conduit port 68 is a supply or input port and housing port 48 is areturn or output port, although the invention is not limited to fluidflow in opposite directions.

Radial seals 110 and 110′, FIG. 11, are preferably disposed between theproximal inner wall 104 of the stator portion of the housing and thedistal outer wall 102 of the rotor portion of the housing and adjacentbearing assembly 100. Radial seals 110, 110′ are typically attached tothe proximal inner wall 104 of the stator portion of the housing.

In the preferred embodiment, all of the flow ports 50, 66, 48, 68, seeFIG. 4, are located proximate the outer periphery of the union. The sumof the perimeter of the rotor ports 50 and 66 is a dimension the sameorder of magnitude as the perimeter of the rotor portion 46 and the sumof the perimeter of the stator ports 48 and 68 is a dimension the sameorder of magnitude as the perimeter of the stator portion 44, providingfor increased fluid flow. In one example, all of the ports were 3.5inches in diameter and the housing was 11.5 inches in diameter at itslargest portion. Also as shown, both of the rotor ports 50, 66 arelocated proximate the periphery of the rotor portion 46 and both of thestator ports 48, 68 are located proximate the periphery of the statorportion 44, with the dimensions and locations of the ports so as tofacilitate a large flow volume and facilitate plumbing connections.

A working model of the dual flow rotating union of the present inventionwas 17.375 inches high and 11.5 inches wide, weighing approximately 28pounds. The prototype was able to accommodate a flow of 230 gallons perminute of coolant with oscillating motion of +/−220° oscillating motionat 5 rotations per minute, for three 600 hour intervals, 24 hours a day,7 days a week, replicating conditions typically found in an antennaassembly aboard a U.S. Navy ship. The working model of the dual flowrotating union was made of metal. Those skilled in the art willunderstand that for specific structural designs the width, height, portsize, and material are all design variables to be taken into account,and others may be used.

The dual flow rotating union of the present invention is morestreamlined, lighter weight, less complex, more robust and improved. Byconfiguring the flow ports parallel to the axis of rotation of theunion, the subject invention can be used in relatively small spaces. Byutilizing radial seals, the size of union is further minimized, and theinvention eliminates the difficulties encountered when rotating unionsare utilized in systems which oscillate and are subject to large shockloads. By having a serpentine conduit and a housing each having opposinginput and output flow ports on their stationary and rotating portions,the present invention provides for a large volume of fluid or coolant toflow through the rotating union in opposite directions. Moreover, theseepage port of the present invention provides leak containment that mayoccur with radial seal wear.

Dual flow rotating unions in accordance with this invention are notlimited to phased array antenna systems or coolant delivery, but may beused on any system requiring fluid delivery as well as for the transferof fluid from stationary to rotating platforms, and may include multiplehousings to create multi-channel systems.

Although specific features of the invention are shown in some drawingsand not in others, this is for convenience only as each feature may becombined with any or all of the other features in accordance with theinvention. The words “including”, “comprising”, “having”, and “with” asused herein are to be interpreted broadly and comprehensively and arenot limited to any physical interconnection. Moreover, any embodimentsdisclosed in the subject application are not to be taken as the onlypossible embodiments.

Other embodiments will occur to those skilled in the art and are withinthe following claims:

1. An antenna assembly comprising: a first rotating pedestal includingan antenna thereon; a second pedestal supporting the first pedestal; anda dual flow rotating union having a longitudinal axis and comprising: arotating housing portion coupled to the first rotating pedestal; astationary housing portion coupled to the second stationary pedestal, aconduit located in the housing portion, the conduit having opposingports oriented parallel to the longitudinal axis, the conduit having arotating section and a stationary section, one said conduit port locatedon the rotating section, the other said conduit port located on thestationary section, the housing also having opposing ports orientedparallel to the longitudinal axis, one said housing port located on thestationary portion, the other said housing port located on the rotatingportion.
 2. The antenna assembly of claim 1 in which the conduit curvessuch that a distal end of the rotating section of the conduit rotatablymates with a proximal end of the stationary section of the conduit at alocation on the longitudinal axis of the union.
 3. The antenna assemblyof claim 2 in which the distal end of the rotating section of theconduit is received in the proximal end of the stationary section of theconduit.
 4. The antenna assembly of claim 3 further including a bearingbetween the proximal end of the stationary section of the conduit andthe distal end of the rotating section of the conduit.
 5. The antennaassembly of claim 3 further including a seal between the proximal end ofthe stationary section of the conduit and the distal end of the rotatingsection of the conduit.
 6. The antenna assembly of claim 3 furtherincluding a combined seal and bearing disposed between the proximal endof the stationary section of the conduit and the distal end of therotating section of the conduit.
 7. The antenna assembly ion of claim 6in which the combined seal and bearing is made of carbon and teflon. 8.The antenna assembly of claim 7 further including a bearing assemblydisposed between a distal outer wall of the rotating portion of thehousing and a proximal inner wall of the stationary portion of thehousing.
 9. The antenna assembly of claim 8 further including a radialseal disposed between the distal outer wall of the rotating portion ofthe housing and the proximal inner wall of the stationary portion of thehousing.
 10. The antenna assembly of claim 9 further including a seepageport disposed between the proximal inner wall of the stationary portionof the housing and a proximal outer wall of the stationary portion ofthe housing.
 11. The antenna assembly of claim 1 in which the rotatingportion of the housing has a distal outer wall rotatably received withina proximal inner wall of the stationary portion of the housing.
 12. Theantenna assembly of claim 1 in which the rotating section port of theconduit is disposed adjacent the rotating port of the housing and thestationary section port of the conduit is disposed adjacent thestationary port of the housing.
 13. The antenna assembly of claim 1wherein the rotating portion of the housing has an axis of rotation thesame as the longitudinal axis.
 14. The antenna assembly of claim 1wherein the rotating section of the conduit has an axis of rotation thesame as the longitudinal axis.
 15. The antenna assembly of claim 1wherein the housing forms another conduit between the housing portlocated on the stationary portion and the housing port located on therotating portion.
 16. The antenna assembly of claim 1 wherein therotating portion of the housing oscillates.
 17. The antenna assembly ofclaim 1 wherein the rotating portion of the conduit oscillates.
 18. Theantenna assembly of claim 7 wherein the rotating portion of the housingoscillates as one unit with the rotating section of the conduit.
 19. Theantenna assembly of claim 1 wherein flow through the conduit is in adirection opposite flow through the housing.
 20. An antenna assemblycomprising: a first rotating pedestal including an antenna thereon; asecond pedestal supporting the first pedestal; and a dual flow rotatingunion having a longitudinal axis and comprising: a rotating housingportion coupled to the first rotating pedestal; a stationary housingportion coupled to the second stationary pedestal, a conduit located inthe housing portion, the conduit having offset opposing ports orientedparallel to the longitudinal axis, the conduit having a rotating sectionand a stationary section, one said conduit port located on the rotatingsection, the other said conduit port located on the stationary section,the housing also having opposing ports oriented parallel to thelongitudinal axis, one said housing port located on the stationaryportion, the other said housing port located on the rotating portion.